Automated closed recirculating aquaculture filtration system and method

ABSTRACT

The present invention is an automated aquaculture system which comprises: one or more culture tanks connected to a closed system of filters and ultraviolet or ozone sources for water purification prior to returning water to the culture tanks. Also disclosed as part of the system are automated biofilters that automatically monitor water conditions in the system, and video cameras in the tanks that monitor growth and condition of the animals in the tank. This invention is also a process useful for culturing an aquatic species, using the disclosed systems. Preferred species include shrimp, squid, marine fishes and fingerlings and marine mollusks.

This is a continuation-in-part of provisional application Ser. No.60/022,176, filed Jun. 24, 1996.

BACKGROUND OF THE INVENTION

This invention relates to automated aquatic systems for the culture ofaquatic species.

Conventional aquaculture systems typically require significant amountsof human intervention in order to enable a species of interest to begrown and cultured. Such systems are not "closed," instead requiringpartial water changes and the like. In large systems, significantamounts of water may need to be used and disposed of. A system which isautomated and truly closed would be advantageous.

SUMMARY OF THE INVENTION

This invention provides a solution to one or more of the problems and/ordeficiencies described above.

In one respect, the present invention is an automated aquaculture systemwhich comprises: a tank; a prefilter system connected to the tank whichcomprises a particulate filter, a foam fractionator and a carbon filter;an aerobic biofilter; a pump that receives effluent from the prefiltersystem and moves the effluent to the aerobic biofilter; a source ofultraviolet light that is in cooperation with the aerobic filter andthat treats water from the aerobic filter, wherein the source isconnected to the tank so that treated water is returned to the tank; ananaerobic biofilter that is connected to the aerobic biofilter forreceiving effluent and connected to the prefilter system for introducingeffluent to the prefilter system; a video camera directed into the tankfor receiving information; and a computer that receives information fromthe cameras and other sensors in the system and that controls theoperation of the system.

In another respect, this invention is a process useful for culturing anaquatic species, comprising:

housing the aquatic species in a tank containing water;

introducing water from the tank into a particulate filter;

introducing effluent from the particulate filter to a foam fractionator;

introducing effluent from the foam fractionator to a carbon filter;

pumping effluent from the carbon filter to an aerobic biofilter;

irradiating effluent from the aerobic biofilter with ultravioletradiation;

treating effluent from the aerobic biofilter in an anaerobic biofilterand returning effluent from the anaerobic biofilter to the system; and

introducing effluent from the irradiating step to the tank.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a closed aquaculture system including a culture raceway(tank), prefilter system, pumping means, aerobic biofilter, anaerobicbiofilter, mechanical pump connected to the anaerobic biofilter, asource of UV light, and connections between the various components whichare depicted by arrowed lines.

FIG. 2A depicts an end view of a culture tank which shows a trough thatruns longitudinally down the middle of the tank and which shows that thefloor of the tank is graded at an angle so that debris flows toward thetrough when the tank is agitated appropriately.

FIG. 2B depicts a side view of an aquaculture system.

FIG. 3 depicts an example of submergence (S). The top of the verticalAir Lift (AL) is the discharge orifice (DO). The top dashed line is thewater level (WL). The bottom dashed line is the injected air (IA). Atthe bottom of the air lift is the injector (I). The distance from WL toDO is Z₁. The distance from WL to IA is Z_(S). The formula forsubmergence is S=Z_(S) /(Z_(S) +Z₁).

FIG. 4 depicts the design of the opening that releases air into theairlift of an aquaculture system.

FIG. 5 depicts a foam fractionator.

FIG. 6 depicts a submerged aerobic biological filter.

FIG. 7 depicts an automated aerobic upflow bead filter.

FIG. 8A-FIG. 8D depicts the water quality history from the system ofFIG. 1. Representative measurements are shown from the hatchery (days1-100) and raceway (days 101-242). The biomass increased from <10 gramsat day 1 to >200 gms per cubic meter in the last third of the cultureperiod.

FIG. 8A depicts the pH measurements during the culture period. Thehorizontal line indicates the desired standard of >8.0.

FIG. 8B depicts the ammonia measurements during the culture period. Thehorizontal line indicates the upper acceptable limit.

FIG. 8C depicts the nitrite measurements during the culture period. Thehorizontal line indicates the upper acceptable limit.

FIG. 8D depicts the nitrate measurements during the culture period. Thehorizontal line indicates the upper acceptable limit.

FIG. 9 depicts a closed aquaculture system including a culture tray,prefilter means, pumping means, automated aerobic biofilter, a source ofUV light and connection between the various components.

FIG. 10A-FIG. 10C depicts the water quality history from the system ofFIG. 9.

FIG. 10A depicts the nitrate concentration, indicating the removal ofnitrate when the denitrifying bioreactor was added. Triangles representinflow and squares represent outflow.

FIG. 10B depicts the nitrite concentration, indicating the removal ofnitrite when the denitrifying bioreactor was added. Triangles representinflow and squares represent outflow.

FIG. 10C depicts the hydrogen sulfide concentration, indicating theremoval of hydrogen sulfide when the denitrifying bioreactor was added.Triangles represent inflow and squares represent outflow.

FIG. 11 depicts a model describing the function of the closedaquaculture system.

FIG. 12 depicts an adaptive network based fuzzy inference driven machinevision classification system for aquaculture in block diagram form.

FIG. 13A-FIG. 13D depicts imaging equipment for the machine visionsubsystem of the present invention.

FIG. 14 depicts image digitization and processing for the machine visionsubsystem of the present invention.

FIG. 15 depicts in block by block diagram the software use anddevelopment for the machine vision subsystem of the present invention.

FIG. 16 depicts the error involved in training a traditional machinevision system. The squares indicate training error and the circlesindicate checking error.

FIG. 17 depicts the error involved in training the ANFIS machine visionsystem. The X indicate checking error and the circles indicate trainingerror.

DETAILED DESCRIPTION OF INVENTION

This invention is the merging of artificial intelligence of establishedprocess control technology and aquatic systems design to provide closed,recirculating water filtration systems to the aquaculture/aquariumindustries. Closed, recirculating aquaculture filtration systems are acollection of subsystems that provide complete ecological life supportfor aquatic organisms, eliminating deliberate replacement of water yetmaintaining acceptable water quality. Implied in this definition is thecomplete removal of biologically generated soluble and suspendedpollutants and conservation of water resources. The definition does notextend to water lost to evaporation. It is assumed that evaporated wateris free of environmental pollutants and its replacement will not resultin substantial resource depletion. The invention relates tomachine/computer control of the processes that optimize the growth andreproduction of aquatic organisms in "closed-loop" biological filtrationsystems. The invention works by continually monitoring of physicalfactors affecting physiological requirements of the cultured organismsand continually adjusting necessary to meet these requirements; somefactors (e.g., dissolved oxygen, pH, metabolites and salinity) will beheld within critical limits while others (e.g., temperature and lightcycle) may be changed to alter growth characteristics and/or periodicityof reproduction.

A closed, recirculating aquaculture system is a collection of tank(s),plumbing, filtration devices, and pumps (FIGS. 1 and 2). The culturetanks may be of any size, shape and material appropriate to the speciesin culture. Plumbing may be of any size, shape and material compatiblewith the overall tank design. The filters used in aquaculture systemsgenerally fall into five types and may be used in any combinationappropriate to the species in culture. The filter types are: (1)particulate removal-screens, settling basins, media filled traps and tosome extent, physical/chemical adsorption devices (foam fractionatorsand activated carbon); (2) physical adsorption-foam fractionators (i.e.,protein skimmers) of all designs; (3) chemical adsorption-activatedcarbon, zeolites and other synthetic media and membranes used to trapmolecules based on size or electrical charge; (4) biological-media bedsthat support bacteria for oxidizing organic wastes and reducing the endproduct(s) to carbon dioxide and elemental nitrogen. In addition,denitrification (the conversion of nitrate into nitrogen gas) can occurin biological filter beds under anaerobic conditions; and (5)irradiation/oxidation--a group of devices producing ultraviolet light(UV), ozone or both.

Pumps may be any of a number of devices used to move water through thesystem at a rate compatible with the overall tank design and animals.Included in this category are water pumps, air blowers and compressors.A natural dichotomy between mechanical, pump-driven systems andairlift-driven systems occurs in the design of filtration.Airlift-driven systems operate at very low head pressure but with flowvolumes equal to pump-driven systems that operate with high headpressure. There are a number of compelling reasons (e.g., economy,simplicity and durability) to use airlifts in aquaculture systems.However, aquaculture filtration systems are typically pump-driven.Filters designed for high pressure pumping are readily available andentirely adaptable to the requirements of this invention but they arenot easily adapted to airlift-driven systems. Therefore, filtersdescribed as part of this embodiment are low pressure designs developedfor airlift-driven systems but they are appropriate for pump-drivenapplications.

All systems and subsystems are integrated by an intelligent controlsystem composed of sensors, communication devices, computer hardware,software interface and expert system. These control systems: (1) acquirereal-time data directly from production systems, (2) transform theinputs mathematically into process models, (3) interface these modelswith expert systems that assume the role of a human expert, and (4)apply decisions of the expert system to control critical processes.Therefore, the development of automated aquaculture systems should bedriven by the expansion of intensive aquaculture systems and theincreased availability of affordable process control hardware andsoftware. Success in designing a pragmatic and affordable automatedcontrol system will be widely applicable because it will greatly enhancewater management, reduce costs associated with manual monitoring andreduce significantly the chance of catastrophic system failures. Themodem commercial aquaculture facility has become a sophisticated networkof interrelated processes and subprocesses that require the transfer ofraw materials (e.g., oxygen, heat, feeds and water) into a high-qualityfinal product (edible high protein flesh) at a rapid rate. Theseprocesses are comparable to the physical processes managed bymanufacturing industries. They require many simple (step-wise) andcomplex (side-loop) processes to be integrated spatially and temporallyin order to maximize product and minimize failures. Automation ofintensive aquaculture systems will allow US companies to: (1) competewith world commodity markets by locating production closer to markets,(2) improve environmental control, (3) reduce catastrophic losses, (4)avoid problems with environmental regulations on effluents, (5) reducemanagement and labor cots significantly, and (6) improve product qualityand consistency. The application of process control technology and theconcurrent need for aquaculture-specific expert systems (a computerprogram that supplies answers or solutions based on availableinformation, by attempting to duplicate the human thought process) iscentral to continued intensification of the aquaculture industry.

In addition, the invention includes a machine vision subsystem that is aprocess by which organisms may be modeled for the purposes of detection,surveillance, measurement and quality assessment in a machine visionsystem. The machine vision subsystem is the application of anadaptive-neuro fuzzy inference system (ANFIS) to the problems ofsingulation (identifying an individual in a frame) and segmentation(separating an object from the background) and intelligent continuousmonitoring in an aquacultural or agricultural system.

In an automated aquaculture system, the machine vision subsystem may beused to incorporate animal data into the control parameters for thesystem. This animal data may include size, growth rates, activity level,activity classification (e.g., mating behavior, egg laying and molting).Animal data can be used as an environmental indicator (e.g., waterquality alarms) or as a control variable (e.g., mating behavior causesan increase in feeding frequency) for an automated system. The machinevision subsystem is the necessary missing link between the theoreticaluse of machine vision in aquaculture and the ability for the applicationof machine vision technology in any production facility. Productionfacilities where organisms are products or producers (agriculture,aquaculture, and biotechnology) will benefit the most since thisinvention makes possible the use of machine vision for scenes and targetobjects which are irregular and complex.

The machine vision subsystem consists of a process (algorithm) wherebyfeatures (whether they are part of the a priori knowledge of targetobject morphology for the purposes of object recognition andclassification, the results of a continuous activity monitor, or thetest for animal or product marketability) are grouped with a cooperativeeffort of supervised learning (neural networks) and a fuzzy inferencesystem (FIS). The supervised learning may take place in batches, withthe end product being a FIS which will operate (make decisions) withoutthe continued application of machine learning; or, the learning may takeplace on line whereby the Neural Network will continue to modify the FISwithin predetermined parameters, and thus improve performance and thediscernment capabilities of the system via unsupervised learning.

This invention, a computer automated closed, recirculating aquaculturefiltration system (CACRAFS), is recognized as utilitarian to theindustry and necessary to the environment. It was previouslyunattainable because artificial intelligence capable of the complex"decision making" to control biological filtration was lacking.Biological filtration of aquaculture water is essential to the healthand survival of aquatic animals. Automated control of thedenitrification subprocess was developed and patented in U.S. Pat. No.5,482,630, incorporated herein by reference. The final piece iscontributed by the machine vision subsystem.

Filtration Subsystems

The serial arrangement of filters (FIG. 1) is ordered such that effluentwater is contracted in the following plug-flow order: (1) mechanical orparticulate filtration (e.g., submerged bed, upflow sand or bed filter,fluidized sand filter, semipermeable membrane, flushing filter andtrickling filter); (2) physical adsorption or foam fractionation (e.g.,protein skimmers); (3) chemical (e.g., activated charcoal, zeolite orany chelating or sequestering compound); (4) biological (e.g., aerobicor anaerobic bacterial beds that function as heterotrophic orchemoauxotrophic bacterial assemblages); and (5) sterilization (e.g.,ultraviolet light, ozone, chlorine or other chemical oxidants).

The sequence is appropriate for all forms of aquaculture filtrationcomponents as listed above. A typical arrangement of the system is shownin FIG. 2B in which the prefilter tank 22 (including the particulatefilter, foam fractionator and activated carbon) have dimensions of4'W×8'L×4'H. The culture tank 10 has dimensions of 12'W×20'L×4'H. Theairlift casing 55 is 24" in diameter×13'H and the biofilter 60 is8'W×18'L×3'H. The head tank 52 is 2'W×4'L×2'H. Also shown in FIG. 2B aretwo ultraviolet light sterilizers 80.

Filtration efficiency is managed by a distributed control system, DCS(using artificial intelligence) so that water quality is maintained atacceptable standards for any aquatic species in culture. The five filtertypes are automated in the following manner: (1) the efficiency ofmechanical or particulate filtration can be improved by monitoringdifferential pressure across the filter, water flow through the filter,oxidation-reduction potential, dissolved oxygen and filter bed expansionvolume and by then controlling water flow rate or residence time,backwashing frequency and duration; (2) the efficiency of physicaladsorption can be improved by monitoring water flow through the filter,total gas pressure in the effluent, gas injection and bubble height andby then controlling water flow rate or residence time, cycle time, gassource (e.g., blower air, compressed gas or ozone) and gas injectionrate; (3) the efficiency of chemical filtration can be improved bymonitoring water flow through the filter and differential pressureacross the filter and by then controlling water flow rate or residencetime; (4) the efficiency of biological filtration (e.g., aerobic oranaerobic) can be improved by monitoring water flow through the filter,differential pressure across the filter, dissolved oxygen, pH,oxidation-reduction potential, carbon dioxide and water level changesdepending on the type of biological filter used (e.g., submerged,upflow, fluidized, trickling or flushing) and by then controlling waterflow rate or residence time, dissolved oxygen injection, bufferinjection, backwashing frequency and duration; and (5) the efficiency ofsterilization can be improved by monitoring water flow through thefilter, light intensity and wavelength (ultraviolet) andoxidation-reduction potential (ozone and chemical oxidants) and by thencontrolling water flow rate or residence time and chemical injection(ozone and chemical oxidants).

Airlift pump design and operation are improved by: (a) the design of theairlift injector. Air bubble size configuration influences airliftefficiency. The diffuser orifice is a modified tear drop shape beginningas a slit at the top to produce smaller (<1-10 mm id.), slower risingbubbles then expanding to a circular base to produce larger bubbles(10-30 mm id.) (FIG. 4); (b) the air-water slurry exiting the top of theairlift pipe is deflected away from the top of the pipe by a cone-shapedstructure. The cone-shaped structure deflects water away from the top ofthe airlift so that it does not fall straight down and impede waterflow.

In FIG. 1 there is depicted a system which includes a raceway (culturetank) 10. The culture tank 10 may have a configuration as depicted inFIG. 2, which includes a trough 12 and angled floor 14. In FIG. 1,effluent from culture tank 10 enters a prefilter system 22 that includesparticulate filter 20, foam fractionator 30 and carbon filter 40. Theculture tank 10 is connected to the prefilter system by a conduit whichis depicted by arrowed lines 16. The particulate filter 20 serves tofilter larger debris from the culture tank. Effluent from particulatefilter 20 flows into foam fractionator 30 where foam is removed. Thefoam fractionator 30 may be of the configuration depicted in FIG. 5.Effluent from the foam fractionator 30 then enters carbon filter 40 foradditional prefiltration. Effluent from the carbon filter 40 then flowsthrough a conduit depicted by arrowed line 42 to an airlift 50. Theairlift is depicted in greater detail in FIG. 5, as well as FIG. 4,which shows the design of the opening that releases air into theairlift. The airlift 50 is composed of a airlift tank 54 and a verticalpipe 55 which dimensions may vary depending on the size of the system.At the base of the pipe for airlift 55, air injector 53 introduces airwhich rises and thereby draws water up the airlift, thereby providingpumping action and circulation. Water from airlift 50 enters head tank52 and then pours into aerobic biofilter 60. The aerobic biofilter 60may contain gravel, which serves to support microorganisms which serveto perform the aerobic biofiltration. Effluent from aerobic biofilter 60then flows into UV light source 80 via conduit 62. The UV light source80 irradiates the water to thereby kill microorganisms and pathogensthat may be found in the water. Effluent from the UV light source 80 isreturned to the culture tank 10 via conduit 82. Intermittently, effluentfrom the aerobic biofilter 60 is sent to anaerobic biofilter 70 viaconduit 64. The anaerobic biofilter 70 may be of a design as depicted inU.S. Pat. No. 5,482,630. Effluent from the anaerobic biofilter is thenpumped via mechanical pump 72 through conduit 74 into particulate filter20. The anaerobic biofilter 70 serves to remove nitrates from thesystem.

The foam fractionator 30 (protein skimmer) has louvered slots 31positioned on the contact chamber 32 several centimeters below the waterlevel of the vessel holding (FIG. 5). The louvered slots are directedinward so that water entering the contact chamber 32 is deflected toform a circular pattern as it travels downward to the exit. This design:(1) increases water residence time for more efficient organic removal;(2) allows small air bubbles to coalesce into larger bubbles that canrise faster against the countercurrent of water, and (3) concentratesthe bubble mass in the center of the cylinder so that it does not escapethrough the louvers.

The design of the submerged biological filter bed (FIG. 6) differs fromtypical submerged beds in several key characteristics: (1) the bed 61 iselevated so that it is just submerged at the surface; and (2) incoming(untreated) water is injected below the bed and rises through it (FIG.6). This configuration: (a) reduces compaction of the bed and subsequentreduction of flow; (b) forces organic laden water to contact the darkside of the bed thus limiting the growth of heterotrophs, and (c) causesthe bottom of the bed to contact oxygen rich water thus preventing thedevelopment of anaerobic regions deep in the bed. The design of theautomated upflow bead filter 90 (FIG. 7) is also unique in that in situsensors monitor the bacterial metabolism in the bed 92 and are used tocontrol the environmental parameters, residence time, and backwashschedule. The embodiment shown in FIG. 7 includes a propeller 94 drivenby a propeller motor 96. A valve 98 controls influent. and separateconduits are provided for the addition of oxygen 100 and buffer 102.Another valve 110 controls effluent. In situ sensors monitor dissolvedoxygen 112, differential pressure 114, water flow 116, pH 118, andoxidation-reduction potential 120 in the bed 92 and at the bottom of thefilter 90. A drain 122 is also provided. The configuration optimizes theupflow bead filter's ability to serve a dual action of particlefiltration and nitrification filter.

The culture tank where the cultured organisms lives is self-cleaning.The floor of the tank 14 is modified so that it slopes (e.g., 2inches/ft.) to the middle where a (e.g., 4-inch) trough 12 is located.The tank outlet is located at one end of the trough and collected wastesare removed to the particle filter. The concentration of waste in thetrough and collected wastes are removed to the particle filter. Theconcentration of waste in the trough is also facilitated through the useof bubble screens (aeration injectors) located directly above the drain.As a result, most of the wastes are flushed from the tank, requiring nolabor.

Distributed Control Subsystem

An integrated process control system is utilized for the distributedcontrol of the aquaculture production and filtration subsystems. Thedistributed control system (DCS) is composed of multiplesensors/transducers that convert environmental conditions intoelectrical signals, communication multiplexers that convert the sensor'selectrical signals into digital code, computer hardware that can receivethe transmitted signals from and to the multiplexers, computer hardwarethat interfaces to the human user and computer software configured toprovide a graphical interface for representing floor plans, trendingincoming data and trending historical data. In addition, high levelintegration of the control loops is managed by artificial intelligencecomputer programs (e.g., rule-based expert system, neural nets,fuzzy-logic-based expert systems, and neural fuzzy systems). Trainingset parameters include dissolved oxygen levels, salinity andconductivity, water level, pumping rates, pump effort, flow rates,temperature, heating and/or cooling effort, buffer addition based on pH,oxidation/reduction potential, seawater or water addition based on waterlevel and salinity.

The DCS is used in conjunction with appropriate mathematical models(e.g., on/off, PID, statistical models or expert systems) forenvironmental monitoring and control in all culture and filter tanks(FIG. 11): (a) temperature monitoring and control; (b) pH monitoring andcontrol; (c) salinity monitoring and control; (d) oxidation/reductionpotential (ORP) monitoring and control; (e) dissolved carbon dioxidemonitoring and control; (f) total dissolved gases monitoring andcontrol; and (g) dissolved oxygen monitoring and control.

The DCS is used in conjunction with appropriate mathematical models(e.g., on/off, PID, statistical models or expert systems) to manage allfiltration devices (FIG. 11). Sensor inputs (e.g., pressure, level, ORPand dissolved oxygen) are used to monitor the function of the filtrationsystems (e.g., particle, carbon, and biological). Based on themathematical control models, outputs control various functions such aswater flow or residence time, backwashing and filter maintenanceschedules.

All flow rates within and between filter components are monitored andcontrolled by the DCS. Changes in flow rates within and between filtercomponents are performed by programmed machine intelligence and the DCSfollowing evaluation of the water quality data, e.g., pH, dissolvedoxygen, temperature, salinity (sea water systems only), ORP andturbidity.

The DCS is used for water level monitoring and control in all cultureand filtration tanks used by the CACRAFS. Accurate control of waterlevels is necessary for flow rate stabilization in airlift-drivensystems.

The DCS produces automated reports of critical systems functions andalarms (local and remote) when system parameters are out of setpoint.Alarms are both visual (strobe and message center) and audible (bell).

The DCS includes feed management capabilities with automated feeders asoutputs and inputs from the machine vision subsystem and internaltimers.

The DCS controls the photoperiod in all culture areas and is used toalter life cycles. The systems can turn lights on/off as well as controlthe level of lighting with rheostats.

FIG. 11 is a model for the function of a closed aquaculture system asshown in FIG. 1 or FIG. 9. The boxes are state variables, the spigotsare transfer coefficients and the circles are effects. The modelsubsystem at the top is Animal Biomass 300. The state variable is gramsof biomass 302. The effects are grams growth 304, growth in grams 306,number 308, weight in grams 310, kilos per cubic meter 312, tank volumeI 314 and value $316.

The second model subsystem is cumulatives 340. The state variables aretotal feed kg 342, cumulative TAN (total ammonia nitrogen) 344 andbiomass in grams 346. The effects are feed in kg 348, feed cost 350,Daily TAN gm 352, wasted feed 362, TAN biomass 354, nitrification 356,TNN biomass 358 and nitrification biomass 360.

The third model subsystem is total ammonia nitrogen 370. State variablesinclude biomass gm 372, total ammonia nitrogen 374, bead filter 376 andsand filter 378. Effects are nitrogen content 380, feed rate 382,nitrogen feed gm day 384, assimilation rate 386, wasted feed 388, NH₃ mgI 390, NH₃ concentration gm I 392, Tank volume I 394, main flow rate396, TAN to bead filter 398, bead filter nitrification 400, TAN to sandfilter 402, Sand filter nitrification 404 and TAN return 406.

The fourth model subsystem is denitrification 420. State variables areTNN (total nitrate nitrogen) 422 and bioreactor 424. Effects arenitrification 426, bead filter nitrification 428, sand filternitrification 430, NO₃ concentration mg I 432, NO₃ concentration gm I434, tank volume I 436, TNN to bioreactor 438, denitrification 440,bioreactor efficiency 442, columns 444, bioreactor volume 446,bioreactor flow 448, residence time 450 and TNN return 452.

The mathematical model is as follows:

Animal Biomass

Biomass₋₋ gm(t)=Biomass₋₋ gm(t-dt)+(Growth₋₋ gm)*dt

INIT Biomass₋₋ gm=Number*0.0020 {2 mg PLs}

INFLOWS:

Growth₋₋ gm=(Grams₋₋ Growth/7)*Number

Kilos₋₋ per₋₋ cu₋₋ meter=Biomass₋₋ gm/Tank₋₋ Vol₋₋ I

Number=154800 {400 animals/m3 @25 gms & 10 kg/m3}

Value₋₋ $=(Biomas₋₋ gm*2.2*6)/1000

Weight₋₋ gm=Biomass₋₋ gm/Number

Grams₋₋ Growth=GRAPH(time) (0.00, 0.25), (7.50, 0.26), (15.0, 0.26),(22.5, 0.278), (30.0, 0.312), (37.5, 0.407), (45.0, 0.54), (52.5,0.915), (60.0, 1.11), (67.5, 1.18), (75.0, 1.20), (82.5, 1.20), (90.0,1.20), (97.5, 1.20), (105, 1.20), (113, 1.20), (120, 1.20), (128, 1.20),(135, 1.20), (143, 1.20), (150, 1.20)

Cumulatives

Cum₋₋ TAN(t)=Cum₋₋ TAN(t-dt)+(Daily₋₋ T₋₋ A₋₋ N₋₋ gm)*dt

INIT Cum₋₋ TAN=0

INFLOWS:

Daily₋₋ T₋₋ A₋₋ N₋₋ gm=Wasted₋₋ Feed

Total₋₋ Feed₋₋ kg(t)=Total₋₋ Feed₋₋ kg(t-dt)+(Feed₋₋ kg)*dt

INIT Total₋₋ Feed₋₋ kg=0

INFLOWS:

Feed₋₋ kg=((Feed₋₋ Rate/100)*Biomass₋₋ gm)/1000 {kg}

Feed₋₋ Cost₋₋ $=Total₋₋ Feed₋₋ kg*0.6

Nitrification₋₋ biomass=(Nitrification/Biomass₋₋ gm)*1000

Denitrification

Bioreactor(t)=Bioreactor(t-dt)+(TNN₋₋ to₋₋Bioreactor-Denitrification-TNN₋₋ Return)*dt

INIT Bioreactor=0

INFLOWS:

TNN₋₋ to₋₋ Bioreactor=TNN*(Bioreactor₋₋ Flow/Tank₋₋ Vol₋₋ I)

OUTFLOWS:

Denitrification=Bioreactor₋₋ Efficiency*Bioreactor

TNN₋₋ Return=Bioreactor-Denitrification

TNN(t)=TNN(t-dt)+(TNN₋₋ Return+Nitrification-TNN₋₋ to₋₋ Bioreactor)*dt

INIT TNN=0

INFLOWS:

TNN₋₋ Return=Bioreactor-Denitrification

Nitrification=BF₋₋ Nitrification+SF₋₋ Nitrification

OUTFLOWS:

TNN₋₋ to₋₋ Bioreactor=TNN*(Bioreactor₋₋ Flow/Tank₋₋ Vol₋₋ I)

Bioreactor₋₋ Efficiency=0.7

Bioreactor₋₋ Flow=Bioreactor₋₋ Volume*(24/Residence₋₋ Time)

Bioreactor₋₋ Volumne=200*Columns

Columns=6

NO3₋₋ Conc₋₋ gm₋₋ I=TNN/Tank₋₋ Vol₋₋ I

Residence₋₋ Time=2{2 hours, converted to days}

Total Ammonia Nitrogen

Bead₋₋ Filter(t)=Bead₋₋ Filter(t-dt)+(TAN₋₋ to₋₋ BF-TAN₋₋ to₋₋ SF-BF₋₋Nitrification)*dt

INIT Bead₋₋ Filter=0

INFLOWS:

TAN₋₋ to₋₋ BF=NH3₋₋ Conc₋₋ gm₋₋ I*Main₋₋ Flow₋₋ Rate

OUTFLOWS:

TAN₋₋ to₋₋ SF=Bead₋₋ Filter-BF₋₋ Nitrification

BF₋₋ Nitrification=min(Bead₋₋ Filter,250)

Sand₋₋ Filter(t)=Sand₋₋ Filter(t-dt)+(TAN₋₋ to₋₋ SF-TAN₋₋ return-SF₋₋Nitrification)*dt

INIT Sand₋₋ Filter=0

INFLOWS:

TAN-to₋₋ SF=Bead₋₋ Filter-BF₋₋ Nitrification

OUTFLOWS:

TAN-Return=Sand₋₋ Filter-SF₋₋ Nitrification

SF₋₋ Nitrification=min(Sand₋₋ Filter,3750)

T₋₋ A₋₋ N(t)=T₋₋ A₋₋ N₋₋ (t-dt)+(Wasted₋₋ Feed+TAN₋₋ Return-TAN₋₋ to₋₋BF)*dt

INIT T₋₋ A₋₋ N=0

INFLOWS:

Wasted₋₋ Feed=Nitrogen₋₋ Feed₋₋ gm₋₋ day-(Nitrogen₋₋ Feed₋₋ gm₋₋day*Assimilation₋₋ Rate)

TAN₋₋ return=Sand₋₋ Filter-SF₋₋ Nitrification

OUTFLOWS:

TAN₋₋ to₋₋ BF=NH3₋₋ Conc₋₋ gm₋₋ I*Main₋₋ Flow₋₋ Rate

Assimilation₋₋ Rate=0.45

Feed₋₋ Rate=Grams₋₋ Growth*1.8

Main₋₋ Flow₋₋ Rate=(890*3.785)*3600

NH3₋₋ Conc₋₋ gm₋₋ I=T₋₋ A₋₋ N/Tank₋₋ Vol₋₋ I

NH3₋₋ mg₋₋ I=NH3₋₋ Conc₋₋ gm₋₋ I*1000

Nitrogen₋₋ Content=0.4

Nitrogen₋₋ Feed₋₋ gm₋₋ day=Biomass₋₋ gm*(Feed₋₋ Rate/100)*Nitrogen₋₋Content

Tank₋₋ Vol₋₋ I=387374

Not in a Sector

TAN₋₋ Biomass=Daily₋₋ T₋₋ A₋₋ N₋₋ gm/Biomass₋₋ gm

TNN₋₋ Biomass=(Nitrification/Biomass₋₋ gm)*1000

Machine Vision Subsystem

The application of an adaptive neurofuzzy inference system (ANFIS) isused for the purpose of object classification in order to develop anobject recognition model for a machine vision system. Automated imagequality assessment using image quality factors (overall brightness,kurtosis features of the curve describing contrast), expert knowledge(an estimate of animal size, an estimate of thresholding valuesnecessary to segment an animal), a model of the image quality as itrelates to the ability of the machine vision system to accuratelymeasure objects, and a model of image quality as it relates to thecertainty of measurement are developed using ANFIS. Texture based imagemodeling uses an adaptation of the Markov random fields methods. Imagemodeling based on Markov random fields is well known. The presentinvention uses an adaptation of this method involving the addition ofmotion information and the use of a predictive fuzzy model of imageinformation to determine the likelihood of a neighborhood of pixelsbeing the target object.

A part of the present invention is the application of ANFIS for thepurpose of system state classification for the purposes of developing asystem state recognition model for an automated aquaculture system.Rapid object modeling: Using the input of the traditional image analysistools such as Global Lab Image (FIG. 15), the use of ANFIS under thebatch learning mode allows for the rapid development of a FIS thatmodels the target object (FIGS. 16 and 17). The unique step taken hereto rapidly model an object is the use of "natural" groupings from theworld of fuzzy logic.

Another aspect of the invention is the use of machine learning (batch orunsupervised) to monitor the condition of organisms in an automatedaquaculture system. This includes organism condition assessment, inwhich the condition of the organism may be (1) defined using apre-existing knowledge base and/or (2) deduced based on the ANFISprocess of combining target object feature analysis with other parameterdata (such as water quality, temperature, light level) in an automatedaquaculture system. Continuous organism activity monitoring in which theactivity level of the animals, based on gross movement and shaperecognition is incorporated into the automated aquaculture system isalso used. A diagram of the Adoptive-Network-based-Fuzzy InferenceDriven Machine Vision Classification System for Aquaculture (ANFIS) isshown in FIG. 12. The inputs to the "ANFIS" 240 include "a prioriknowledge of target object morphology" 242 and "traditional imageanalysis of segmentation features" 244. The input/output loop in FIG. 12is "natural groupings and operator supervision of intelligent FISdevelopment using batch or continuous learning methods" 246 and theoutputs are "ANFIS continues with unsupervised learning" 248 and "FISalone" 250.

An aspect of the invention, therefore, may be described as the use ofthe results of machine vision as sensor input (i.e., control variable)in an automated aquaculture system.

The Airlift

Key elements in the economical use of this type of water circulationare: (1) submergence (FIG. 3) or the relationship (expressed as apercent) between the depth air is injected to the height water is raised(lifted); (2) the volume of injected air, FIG. 3; (3) the design of theinjector, 1; (4) diameter of the airlift; and (5) the design of thelifted water discharge orifice DO, and head tank. The most efficientairlifts deliver water through an open vertical pipe at the water'ssurface. Efficiency declines as the top of the pipe is raised above thesurface. Theoretically, a submergence below 80% results in veryrestricted water flow volumes. Pipe diameter influences the height oflift and smaller pipe diameters are more efficient at lower (below 80%)submergences. Air bubble size configuration influences airliftefficiency. Small bubbles rise slower and lift water at a slower ratethan large bubbles. Uniform bubble size moves less water than mixedbubble sizes. Two types of injection are commonly used. One type injectsair through a collar outside the airlift pipe and the other injects airthrough a pipe installed inside the airlift pipe. The first designavoids restricting water flow by limiting friction and optimizing thevolume in the pipe.

The novel airlift pump included in this invention has several uniquedesign characteristics. First, the diffuser orifice 53 is a modifiedtear drop shape (FIG. 4) beginning as a slit at the top to producesmaller (<1-10 mm dia.), slower rising bubbles then expanding to acircular base to produce larger bubbles (10-30 mm dia.) (FIG. 4). Thisproduces mixed bubble sizes and broadens the range of control forautomation. Three diffuser orifices are cut into smaller diameter pipe(1/2-2"). The numbers of orifices increase with pipe circumference tothe maximum number that can be evenly spaced leaving enough materialbetween the greatest horizontal diameter of the orifices to firmlyconnect the lower end of the diff-user. Second, for ease of access tothe diffuser, all airlifts used in this invention are engineered withlarger lift tubes 55 so an air pipe with the diffuser attached can beinstalled in the center of the lift tube. Third, the air-water slurryexiting the top of the airlift pipe is deflected away from the top ofthe pipe by a cone-shaped structure. If the top of the airlift were atthe surface of water in a tank the cone would reduce lift efficiency.However, water must be raised some amount (˜10-20 cm) to provide headpressure for circulation through filters. Therefore, the airlift mustempty into a head tank. Several centimeters of the top must extend abovethe bottom of the head tank so that water does not try to flow back downthe airlift before it exits the head tank. Thus, the cone-shapedstructure deflects water away from the top of the airlift so that itdoes not fall straight down and impede water flow. The airlift and headtank can be installed anywhere in the loop. In the interest of safety,it should be down stream from the filter that plugs the easiest (i.e.,particle filters; FIG. 1).

Water circulation through the system is a closed loop through theculture tank(s) and individual filters, e.g., FIG. 1. The portion of thetotal flow that moves through each subsequent component is adjustedusing by-pass loops between components and allows control of theefficiency of filtration, the deployment of expendables and the rate ofwater circulation (˜50-200 gpm). The degree of filtration efficiencymust maintain water quality at an acceptable level and may be adjustedby variable-rate recirculating loops within each component, e.g., thefoam fractionator. All of flow rates within and between components aremonitored and controlled by the distributed control system (DCS).

Particulate Removal

Particulate removal may be accomplished by screens, settling basins,media filled traps and to some extent, physical/chemical adsorptiondevices (e.g., foam fractionators and activated carbon). With theexception of canister type particle traps, most solids removers can bedirectly plumbed into an airlift driven water circuit. The mostpractical designs for airlifts have large surface areas, moving screensand/or sediment traps. The cross sectional design (FIGS. 2A and 2B) ofthe culture tank can be such that solid wastes are massed in the flow ofwater circulation and carried to a solids trap 20. This effect isdependent upon a tank design that is longer than wide and configuredwith the water inlet at one end and the outlet at the other. Airdiffused into the culture tank along the longitudinal axis createscirculation cells at right angles to the longitudinal flow of water andflushes solids particles from the bottom and sides to the center. Solidsthen migrate with the water flow from the inlet end of the tank to theoutlet where they are picked up in the outlet stream and carried to thesolids separator 20. Solids separators should be installed immediatelydownstream from the culture tank. The inlet to the separator shouldempty at the height of the water level in the culture tank so that theculture tank water level stays constant. Alternatively, a low headpressure upflow bead filter (FIG. 7) or sand filter can be used toseparate particles. These latter two systems require backwashing withthe loss of a fraction of system water.

Physical Adsorption

Foam fractionators of all designs can be included but their positionshould be fixed. They should be positioned immediately after theparticulate filter. The primary design constraint is that water flowsdown the fractionator column against a countercurrent of air bubbles.Dissolved and suspended organics adhere to the bubbles and are carriedup a drying tube above the water level. It is transferred from thebubbles to the sides of the drying tube and carried up to a reservoir bythe air stream that produced the bubbles.

The foam fractionator designed for the system described in the specificembodiments (FIG. 5) consists of a cylindrical (contact) chamber 32standing on end and plumbed to an airlift near its bottom. The bottom ofthe cylinder is closed and the top is fitted with a shallow cone 34pointed upward. The cone location is adjustable in the cylinder and itsbase is set at cylinder water level. Void volume decreases toward thetop of the cone condensing foam as it is produced and floats upward. Thepeak of the cone opens into a section of tubing 36 that furthercondenses or "drys" the foam that is carried by the stream of escapingair to a foam collector . In this embodiment the top of the drying tubeis fitted with a venturi 44 that assists escaping air to carry the foamto a reservoir outside the system.

Untreated water enters the foam fractionator contact chamber throughlouvered slots 31 positioned several centimeters below the water levelof the vessel holding the fractionator (FIG. 5). The water is drawn inby an airlift 55 plumbed to the bottom of the contact chamber and theflow rate is adjusted to optimize the formation of foam in thecondensing cone. The louver fins are directed inward so that waterentering the contact chamber travels in a circular pattern. This design:(1) increases water residence time for more efficient organic removal;(2) allows small air bubbles to coalesce into to larger bubbles that canrise faster against the countercurrent of water, and (3) concentratesthe bubble mass in the center of the cylinder so that it does not escapethrough the louvers. The rate at which water can be stripped ofdissolved and particulate organics is dependent upon a water velocitythrough the contact chamber that allows air bubbles carrying theorganics to rise. Therefore, the diameter of contact chamber is animportant factor because as it increases, the distance traveled in eachcomplete circle increases and the volume of water that can be strippedincreases.

Chemical Adsorption

Activated carbon, zeolites, synthetic media and selectively permeablemembranes are used to trap molecules based on size or electrical charge.Filter designs for these media all produce a water flow directed acrossthe media. A typical embodiment for this invention is a vessel fittedwith a false bottom and screen such that water enters the vessel belowthe false bottom and flows upward through the screen and media. Thescreen must be of a mesh size that retains the media but passes thelargest particles that escape the particulate filter. Designs that holdmedia in a vertical configuration against the water flow in a highpressure, pump-driven system tend to become compacted and require morelabor to operate.

Biological

Media beds support bacteria for (1) oxidizing organic wastes to NH₄ andCO₂, and (2) reducing the end product(s) to elemental nitrogen, N₂.Oxidizing beds probably have the greatest variety of designs, mediatypes and operating efficiencies of all the filters and conditioningdevices used in aquaculture. The most common type is the submergedfilter (e.g., under gravel or sand). Wet-dry filters pump water overplastic balls, synthetic and natural fiber mats and other surfaces thatare exposed to the air. Fluidized beds use fine grained particles (e.g.,sand or plastic beads) that are kept in suspension by the flow of waterinjected beneath them. All types have been adapted to function at headpressures produced by airlifts.

The design used in this embodiment of the invention is a modifiedsubmerged bed. However, the design of the bed differs from typicalsubmerged beds in several key characteristics. First the bed is elevatedso that it is just submerged at the surface 64 and incoming (untreated)water is injected below the bed 61 and rises through it (FIG. 6). Thisconfiguration: (1) reduces compaction of the bed and subsequentreduction of flow; (w) forces organic laden water to contact the darkside of the bed thus limiting the growth of heterotrophs; and (3) causesthe bottom of the bed to contact oxygen rich water thus preventing thedevelopment of anaerobic regions in the bed. Second, this elevatedconfiguration allows the area under the bed to be cleaned by extending asiphon through a manway 66. This saves down time and man hours normallyspent dismantling the filter bed. In situ monitoring of filter bedfunction is accomplished with dissolved oxygen and pH probes above andbelow the bed and four oxidation-reduction probes spaced evenly over thefilter bed surface area and inserted halfway into the depth of thefilter bed. These inputs will be used to control water flow through thefilter bed and injection of air or oxygen and buffer into the filtertank. This will optimize filter bed chemoauxotophic bacterialmetabolism.

An alternative nitrifying biofilter is the upflow plastic bead filter(FIG. 7) that functions as a physical filter as well as a biologicalfilter. This filter can perform both functions quite well when operatedoptimally in contrast to submerged filters that are adversely affectedby particulate accumulation (e.g., channelization and bioflocmineralization). An upflow bead filter can accumulate particulates andnitrify when backwashed appropriately. However, optimizing these upflowbead filters requires an expertise that is often lacking in thepersonnel operating them. For this reason, automation of their functionis essential. The operation of the upflow bead filter can be optimizedby monitoring bacterial metabolism in the bed using in situ sensors(e.g. dissolved oxygen 112, oxidation-reduction potential 120, pH 118and flow rate 116) and measuring the pressure drop across the bed due toparticulate accumulation with pressure sensors 114. This embodiment hastwo oxidation-reduction sensors 120 to be placed below and above the bedas well as two more being placed within the bed at 180° intervals aroundthe circular bed 92. In addition, two pH sensors 118 are placed in theopposite 180° configuration. These four sensors are placed in the middleof the bed height. In addition, one dissolved oxygen probe 112 is placedabove and one below the bed. The differential pressure transducer 14 isconnected to the filter influent 130 and effluent 132 piping. The inputsfrom the sensors is used to automate the water flow rate or residencetime, backwash frequency, backwash duration and to inject oxygen andbuffer into the bead filter to optimize the growth and metabolism of thechemoauxotrophic bacteria and inhibit the heterotrophic bacteriaresiding on the beads. If backwashing is too frequent or severe, thechemoauxotrophs will not be able to maintain their position on the bedsand they will be removed from the filter at backwashing. If thebackwashing is not frequent enough, the heterotrophic bacteria willovergrow the chemoauxotrophs and the filter will actual produce ammoniaand other waste products instead of removing them. It is this finebalance that requires automation.

Another example of automated biological filtration is an automateddenitrifying bioreactor described in U.S. Pat. No. 5,482,630. Thisfilter makes it possible to remove the nitrogen from the watercompletely. It is essential to the design of a truly closed aquaculturesystem and is included as a component of the automated, closedrecirculating aquaculture system as described herein.

Sterilization by Oxidation/Irradiation

This group of devices produce ozone, ultraviolet light (UV) or both forthe purpose of sterilization. Ozone is highly corrosive. It is mostsafely used by injecting it into the water processing loop at a pointwhere dissolved organics are most concentrated to facilitate itsreduction. Ozone delivery systems can be used in closed aquaculturesystems without modification. The efficiency of and responsible use ofUltraviolet (UV) light requires a design that insures that all waterpassing through the contactor pass over a specified section of the bulband within a specified distance from the bulb at the specified section,i.e., a lethal contact zone. Less contact could result in the formationof UV resistant strains of bacteria. Economical UV contactor designs forpump-driven systems can not pass enough volume to be effective onairlift driven systems. At head pressures of 15-30 centimeters 1properly configured UV bulb is needed for each 60 liters of watercirculated per minute. Therefore, UV contractors for airlift systemswere designed with (1) larger inlet and outlets; (2) more bulbs, and (3)air purge vents. Installation of the UV contactors in line between thelast filter and the culture tank and below the water level of eachminimizes flow restrictions imposed by low head pressures.

Distributed Control System

The distributed control subsystem is composed of the following elements.An industrial process control system was designed and installed on theabove described tank system. The original design was based on amicrocomputer supervisory control and data acquisition system (SCADA),linking 386/486 series personal computers (PC) with standard industrialcontrol signal multiplexers and software. Currently, the system hasbecome a subprocess in a more comprehensive distributed control system(DCS) that serves three separate aquaculture facilities. Every component(hardware and software) was bought off-the-shelf so that no circuitswere constructed and no computer code was written.

The software used is an intuitive graphical interface product forWindows™ operating environment, DMACS™ for Windows™ by Intellution. Theprogram can run on any 386/486 PC and includes Net DDE, allowingtransfer of data between Windows™ programs. Inputs and outputs can bedisplayed as floor plans, graphs, charts or spreadsheets in real-timeand all data can be archived to the hard disk or other media. Controlfunctions include: set point control, PID(proportional/integral/derivative) control, batch control, statisticalprocess control and custom control blocks. Additional modules allownetworking across typical microcomputer networks and remote operationfrom a dial-in phone line. The computer hardware was a 486 IBM clone PCwith 16 MB (Megabyte) RAM (Random Access Memory), 250 MB hard-disk, 1 MBvideo card and a SVGA Monitor. A Best Systems (Model 660)uninterruptable power supply (UPS) protected the computer from powersurges and would power the computer and monitor for 35 min. during apower outage.

The computer software and hardware was interfaced to an unintelligentsignal multiplexer network (Dutec Model IOP-AD+ and IOP-DE) composed of16 analog and 16 digital inputs/outputs (I/O) channels. Each channelrequired its own signal conditioning module that could accept anyvoltage or current signal (i.e., 4-20 mA, 0-1 V or 0-100 mV). Manydifferent types of I/O were connected to the multiplexer. The racewaycontrol system included monitoring and control of temperature (i.e.,chiller and heaters), pH, salinity (conductivity), dissolved oxygen,water flow rate between tank and filter and water level. In addition,photoperiod control (i.e., relay for overhead lights) and an automaticbelt feeder were installed. The raceway multiplexer was one of four suchmultiplexers connected to the control system. The raceway system wasrepresented on the control system's video monitor as a top view and allmajor functions (i.e., photoperiod, ultraviolet sterilizer state, waterlevel, pH buffer injection and protein skimmer state) were animated foreasy visual determination by the technical staff. Digital displayssimilar to meter displays were created for temperature, dissolvedoxygen, pH, salinity and water flow rate; all inputs and most outputswere archived to a historical data base on the computer hard disk.

Imaging Equipment

(a) An embodiment of the invention as described herein utilizes twoblack and white security cameras 140 (Burhel), a standard RS170 videooutput or two digital cameras consisting of a 1"×1" digital circuitboard on which a video camera is mounted and the fixed focus lens theyutilize (FIG. 13B). The output of these cameras is a standard RS170,although with fewer lines of resolution than the other cameras. Thehousing for these cameras will consist of a small plastic dome housing(4 inches in diameter) fixed and sealed (via a silicone greased o-ring)to a plexi backing.

(b) Each camera is contained in a glass housing comprising a 6"×16"×20"open-top, rectanguloid shape similar to a small aquarium 142 (FIG. 13A).Each housing is topped with a plexiglass lid 144. The lid has twoopenings, one for the cords 146 (power in, video out), the other for theforced air entry. Forced air is an integral part of the housing. Itallows the electronic equipment to operate successfully in a seawaterenvironment. The use of forced air for this purpose is believed to be anovel aspect of the invention.

(c) The camera housing is mounted on each tank by an aluminum bar 148(FIG. 13C) referred to as the "camera mount". The main arms of thecamera mount consist of solid bar aluminum, and the cross pieces aremanufactured from aluminum angle iron. Solid aluminum bar was used forthree reasons: (1) to maintain a rigid lever arm, (2) aluminum will notcorrode dangerously with contact with sea water, and (3) the weight ofthe solid bar helps to compensate for the buoyancy of the housing insalt water. The angle of the mount is adjusted by four bolts which arein contact with the underside of the tanks lids.

(d) An additional weight, in the form of a plastic and epoxy coated boatanchor 149, is used to compensate for the buoyant force of the housing.Compensating for buoyancy and thus reducing the effect of wave action isa necessary part of coping with submerged or partially submergedcameras.

Image Digitization and Processing

The image digitization and processing system is illustrated in FIG. 14.The squid or other animals in the tank 160 are visualized by two cameras140, which are connected via RS232 cable and connectors to a DataTranslation "Frame Grabbing" Board (model #DT3851) 162. This board isresponsible for image digitization and some low level frame processing.The advantages of this board are that the on-board memory may beprogrammed and operations such as frame subtraction, may take place onthe board itself, thus speeding the overall frame processing time. TheData Translation board is mounted in the Machine Vision Computer 164,which also contains an Intel 486/120 MHz motherboard and 16 Mb of RAM.The computer produces an image analysis 166, which is subject to themachine intelligence ANFIS process 167, combining target object featureanalysis with other parameter data, and processed through Dynamic DataExchange (DDE) connections and NetDDE 168 to link the various softwarepackages and report 169 the vision system results to control.

Software

For the development of the systems described herein standard, consumerlevel versions of the following software were used (FIG. 15):

(a) Global Lab Image 182: for image feature extraction, imageenhancement, data collection and the beginning stages of the inventors'statistical recognition model.

(b) Matlab 196 & Matlab's Fuzzy Logic Tool Box 200: for producing aworking fuzzy model as well as the first attempts at using ANFIS, andthe beginnings of the Dynamic Data Exchange (DDE) connections theinventors used to link the various software packages to produce aworking model of their system.

(c) Microsoft Excel: for DDE linkage as well as data storage andmanipulation in the beginning stages of the work.

For the development of the final system, the inventors used thefollowing software libraries and programs:

(d) GLIDE 184: the developer's library containing the source code andall the related functions of the Consumer version of Global Lab Image.

(e) Matlab 196: the consumer version of this product contains resourcesto port Matlab script files to C compilable units.

(f) Borland C++ compiler v. 4.0 186: The inventors made limited use ofthis compiler and development platform in order to port the Matlabgenerated C units to Dynamically Linked Libraries (DLL's) that could beused by the Object-Oriented Application generated using the DelphiApplication Development Program.

(g) Borland Delphi 190: Delphi is an Object-Oriented, Pascal-basedDevelopment Platform. Using it allowed the generation of a uniqueapplication 188 using the programming libraries listed above and theuser interface provided by Delphi. Delphi also includes a powerfullibrary of DDE, Net DDE and Object Linking and Embedding (OLE) objects(or functions). These were essential to the final development of themachine vision system which is linked across the computer network withthe overall control system which uses FixDMACS software.

The final system generated using the developer's version of thedescribed software, as shown in FIG. 15 includes the following:

The imaging system (video camera and capture board) 180 connects to theimage processing global lab 182 software that produces image analysis194, which feeds into MATLAB 196 using the neural networks toolbox 198or the fuzzy logic toolbox 200 to produce the intelligent vision systemmodel 202. Alternatively the image processing global lab 182 connectswith the glide development library 184, and further utilizing theBorland C++ libraries to DLL's 186, and using the Delphi applicationdevelopment software 188 unique programming objects are authored 188 toresult in continuous monitoring 192.

EXAMPLE 1

A 14,500 liter (3,756 US gal.) system used to culture a sensitive marinespecies Sepioteuthis lessoniana (squid) was fully automated andconnected to an automated denitrifying bioreactor. Airlift technologywas developed in 3 other system designs the largest of which consists of2 culture tanks, 2 particle filters, 2 foam fractionators, 2 carbonfilters, 1 biological filter and 2 UV sterilizers. The total volume ofthe system including plumbing and prefilter tanks totals 53,150 liters(16,360 gal.). All systems supported the squid (Sepioteuthis lessoniana)through its life cycle. The automated system maintained squid through 6generations. Airlift-driven systems are in operation with all filtrationand water conditioning devices for low-head pressure application(designed, built, tested and proven). One embodiment (a nursery system)has supported Sepioteuthis lessoniana (squid species) from incubation tolate juvenile stage and another (grow-out) system supported it to theend of its life cycle, including the production of fertile eggs. Thesystem maintained adequate water quality (FIGS. 8A to 8D) as sixgenerations of squid were grown in the system. Another embodiment hasSepia officinalis (cuttlefish species) nearing sexual maturity in itsinaugural culture run. In addition to the squid and cuttlefishproduction systems described above, this invention is applicable to theculture of marine fish and fingerlings.

EXAMPLE 2

A 5,600 liter (1,480 US gal.) culture system used to culturespecific-pathogen-free (SPF) marine shrimp was fully automated andconnected to the required filtration (FIG. 9). The system is composed of2-1,900 L shrimp culture trays 210, a 1.5 hp centrifugal pump 212, a 1m³ computer automated upflow bead filter 214 (FIG. 7), a 2.7 m³submerged oyster shell biofilter 216 (FIG. 6), a protein skimmer/foamfractionator 218 (FIG. 5), a 0.05 m³ activated carbon filter 220, 2ultraviolet sterilizers 222, ozone generator 224 and a denitrifyingbioreactor 226. Also included in the system is a water recovery tank228. The system has been constructed and operated for 2 years. Thesystem has supported shrimp (Penaeus vannamei and Penaeus setiferus)densities as high as 5,000 m² for postlarvae and 50 m² for adultshrimp >15 g. Adult shrimp as large as 20 g have been grown in thesystem and water quality has been acceptable even during systemstart-ups (FIG. 10A-FIG. 10C). The water passes from the culture traysthrough the bead filter, protein skimmer, carbon filter, the submergedbiofilter, UV sterilizers and back to culture trays. A side-loop istaken from the trays, passes through the denitrifying bioreactor andreturns to the submerged biofilter. This type of system would be equallyapplicable to the culture of marine flatfish (e.g. flounder or fluke),other crustaceans (e.g. crabs, crayfish or lobsters) and bivalvemollusks (e.g. clams, scallops and oysters).

What is claimed is:
 1. An automated aquaculture system comprising aclosed, recirculating water system, and further defined ascomprising:one or more culture tanks; a prefilter system which comprisesa particulate filter, a foam fractionator and a carbon filter and isdirectly or indirectly connected to said one or more culture tanks; anaerobic biofilter connected to said prefilter system; a pump that moveswater from the culture tanks through the recirculating system; one ormore sources of ultraviolet light connected to said recirculating systemeffective to irradiate the water in said system prior to return ofirradiated water to said culture tanks, and wherein at least one sourceof ultraviolet light irradiates effluent from the prefilter system; ananaerobic biofilter connected to the recirculating system; and one ormore control systems that monitor and control physical factors of theaquaculture system.
 2. The automated aquaculture system of claim 1,further comprising one or more video cameras directed into the culturetanks for receiving information for transmission to said one or morecontrol systems.
 3. The automated aquaculture system of claim 1, whereinat least one of said one or more control systems utilizes anadaptive-neuro fuzzy inference system for intelligent continuousmonitoring of the aquaculture system.
 4. The automated aquaculturesystem of claim 1, further comprising a computer automated upflow beadfilter system.
 5. The automated aquaculture system of claim 4, whereinsaid computer automated upflow bead filter system comprises an upflowbead filter, and one or more in situ sensors to monitor dissolvedoxygen, differential pressure across the bead filter, water flow, pH oroxidation-reduction potential.
 6. The automated aquaculture system ofclaim 1, wherein said one or more control systems comprise a distributedcontrol subsystem, said subsystem comprising:multiplesensors/transducers that convert environmental conditions intoelectrical signals; communication multiplexers that convert the sensor'selectrical signals into digital code; computer hardware to receive thetransmitted signals from and to the multiplexers; computer hardware tointerface to the human user; and computer software configured to providea graphical interface.
 7. A process useful for culturing an aquaticspecies, comprising:housing the aquatic species in one or more tankscontaining water; introducing water from the one or more tanks into aclosed recirculating water system comprising a serial arrangement offilters, wherein said filters are arranged such that effluent water iscontacted by the filters to effect the following order of treatment: (1)mechanical or particulate filtration, (2) physical adsorption or foamfractionation filtration, (3) chemical filtration, (4) biologicalfiltration; irradiating the effluent from the filters with one or moreultraviolet light sources; and introducing irradiated effluent to theone or more tanks; wherein the physical factors of the water system areautomatically sensed and controlled.
 8. The process according to claim7, wherein process further comprises introducing said water into acomputer automated biofilter that is connected to the water system. 9.The process according to claim 8, wherein said automated biofiltercomprises:a bead bed; one or more in situ sensors for monitoringdissolved oxygen, differential pressure across the bead filter, waterflow, pH or oxidation-reduction potential and for converting theconditions into electrical signals; and an influent conduit below saidbead bed and an effluent conduit above said bead bed; wherein said insitu sensors are connected to a computer.
 10. The process according toclaim 7, wherein said aquatic species is shrimp.
 11. The processaccording to claim 7, wherein said aquatic species is squid.
 12. Theprocess according to claim 7, wherein said aquatic species is a marinefish or fingerling.
 13. The process according to claim 7, wherein saidaquatic species is a mollusk species.